In the NIBCO design stop-checks, you will note that the disc is mounted to permit the disc to settle into the seat area for positive sealing in case there is any misalignment due to assembly or uneven heat expansion.

• 从美国尼伯科的截止止回阀结构设计中，人们可能会注意到，万一出现由于组装问题或不稳定的热膨胀导致的中心线错位，所安装的阀瓣能够适应阀座区域的要求主动调整密封。